1. Straw spatial resolution (beam test 2007 and 2008) A.Zinchenko, S.Shkarovskiy

2. Muon and pion runs(2007), Muon runs (2008) Gas mixture(2007) – CO2+isoC4H10+CF4 (80:10:10) Gas mixture(2008) – CO2+isoC4H10+CF4 (82:5:13) Front end chip – ASD-8 (2007) ASDQ, CARIOCA (2008) Threshold: 6 fC HV: (2200 –2700) V (Gas gain: 210 4 – 10 6 )

3. Comparison ASD-8, ASDQ and CARIOCA Front-End Chips

4. Straw resolution vs R (ASD-8) Ua=+2400 V Gas Gain G=110 5 Straw resolution (sigma) 40x1.2=48 mkm R (cm) Th= 6 fC Th=12 fC Sigma of residuals (cm) Muon runs Straw resolution (sigma) 45 mkm Straw resolution (cm) vs R (cm) (Garfield) Th= 6 fC Th=12 fC

5. Straw residuals vs HV (ASD-8, beam test 2007) Muon+pion runs Th=6 fC for straw R>3 mm

6. Straw residuals vs HV ( ASDQ, CARIOCA ) Beam test 2008, ASDQ Beam test 2008, CARIOCA R = 350 Ohm R = ∞ Ohm R = 350 Ohm R = ∞ Ohm Residual, mkm HV, V Threshold Th= 6 fC, for straw R=3 mm HV, V Straw resolution 40x1.2 = 48 mkm Straw resolution 60x1.2 = 72 mkm

7. Straw residuals vs HV ( ASDQ, CARIOCA ) Beam test 2008, ASDQ Beam test 2008, CARIOCA R = 350 Ohm R = ∞ Ohm R = 350 Ohm R = ∞ Ohm Residual, mkm HV, V Threshold Th= 6 fC, for straw R=3 mm HV, V Straw resolution 40x1.2 = 48 mkm Straw resolution 50x1.2 = 60 mkm

8. R, cm Beam test 2008, ASDQ Beam test 2008, CARIOCA Beam test 2007, ASD-8 GARFIELD, ASDQ GARFIELD, CARIOCA GARFIELD, ASD-8 Ua=2600 V Ua=2500 V Ua=2400 V Ua=2600 V Ua=2500 V Ua=2600 V Ua=2500 V Ua=2600 V Ua=2500 V Residuals, mkm Straw resolution vs R ( ASD-8, ASDQ, CARIOCA )

9. Straw resolution vs R Threshold Th=6 fC ASD-8 HV=2400 V G=1 10 5 ASDQ HV=2500 V G=1 10 5 CARIOCA HV=2600 V G=2 10 5 Resolution, cm R, cm NA62 requerement ASD-8 HV=2400 V G=1 10 5 ASDQ HV=2500 V G=1 10 5 CARIOCA HV=2600 V G=2 10 5 Residual, cm R, cm NA62 requerement Beam test 2007, 2008GARFIELD

10. Amplification vs Wire Voltage GARFIELD Amplification Voltage, V 2375 V2490 V CO2+isoC4H10+CF4 (80:10:10)CO2+isoC4H10+CF4 (82:5:13) dU shift = 115 V

11. Comparison CARIOCA Front-End Chips with transistor and resistor termination

12. CARIOCA cold (2 boards) ch1 ch8 ch1 ch8 ch1 ch8 ch1 ch8 ch1 CARIOCA hot (2 boards) ASDQ (2 boards) Particles Straw far-end Open Hot Open Hot Open Hot Straw near-end Inputs 1 4 3 2 5 6 7 8 1 4 3 2 5 6 7 8 1 4 3 2 5 6 7 8 1 4 3 2 5 6 7 8 1 4 3 2 5 6 7 8 1 4 3 2 5 6 7 8 TDC1 (32 channels) TDC2 (32 channels) # - dead wires # - tubes used for reconstruction CARIOCA cold =transistor termination CARIOCA hot = resistor termination

13. Time spectrum from tube with CARIOCA hot Time spectrum from tube with CARIOCA cold RT-dependence Drift time, ns R,cm

14. Row with CARIOCA resistor termination Sigma residuals = 33.6 μm Row with CARIOCA transistor termination Sigma residuals = 47.2 μm Residuals, cm Straw residuals ( CARIOCA )

15. Straw Efficiency vs Radius (ASD-8, th=6 fC) Ua=+2400 V (G=110 5 ) R effective =4.7 mm Data muon runs R effective =4.8 mm Efficiency vs R (cm) (Garfield)

16. Results ASD-8 resolution (2007): The minimal limit of straw spatial resolution is about 48 µm for gas gain higher than G=110 5 and compare with Garfield simulation result (45 µm) Efficiency (2007): Straw efficiency is about 100% for R effective up to 4.7 mm and compare with Garfield simulation result (R up to 4.8 mm)

17. Results Resolution (2008): The minimal limit on straw spatial resolution for ASDQ (R = ∞) and for CARIOCA (R = ∞) is about 50 µm and compare with Garfield simulation result CARIOCA with resistor termination is better than CARIOCA with transistor termination Slightly wrong definition of RT-dependence and Т0 leads to insignificant degradation of the straw spatial resolution (compare results on slide 6 and 7)

18. Conclusions Comparison ASD-8, ASDQ and CARIOCA FEE: Straw spatial resolution for ASD-8, ASDQ and CARIOCA is about the same. The minimal limit of straw spatial resolution is about 50 µm For gas mixture CO2+isoC4H10+CF4 (82:5:13) HV working point is in the range (2500 – 2600) V -> G=(1-2) 10 5 Comparison CARIOCA termination schemes: CARIOCA with resistor termination is better than CARIOCA with transistor termination ASD-8 8000 channels is available at Dubna